<template>
    <div class="list" ref="wrapper">
      <div>
        <div class="area">
            <div class="title border-topbottom">当前城市</div>
            <div class="button-list">
                <div class="button-wrapper">
                    <div class="button">
                        {{this.currentCity}}
                    </div>
                </div>
            </div>
        </div>
        <div class="area">
            <div class="title border-topbottom">热门城市</div>
            <div class="button-list">
                <div class="button-wrapper" v-for="item of hot" :key="item.id" @click="handleCityClick(item.name)">
                    <div class="button">
                        {{item.name}}
                    </div>
                </div>        
            </div>
        </div>
        <!-- 通过ref将该dom元素和key绑定起来 -->
        <div class="area" v-for="(item, key) of cities" :key="key" :ref="key">
            <div class="title border-topbottom">{{key}}</div>
            <div class="item-list">
                <div class="item border-bottom" v-for="innerItem of item" :key="innerItem.id" @click="handleCityClick(innerItem.name)">{{innerItem.name}}</div>
            </div>
        </div>
      </div>
    </div>
</template>
<script>
import Bscroll from 'better-scroll'
import {mapState, mapMutations} from 'vuex'
export default {
  props: {
    hot: Array,
    cities: Object,
    letter: String
    },
  name: 'CityList',
  mounted(){
    // 要加上一个click参数，否则点击列表内城市没法跳转
      this.scroll =  new Bscroll(this.$refs.wrapper, {click:true})
  },
  watch: {
      letter () {
          if(this.letter){
            //   因为获取到的dom引用是循环得到，所以注意要加上【0】将数组打开
              const element = this.$refs[this.letter][0]
            //   滚动到element对应的 dom的位置
              this.scroll.scrollToElement(element)
          }
      }
  },
  methods: {
    handleCityClick (city) {
      // 传递参数并调用mutation
      // this.$store.commit('changeCity', city)
      this.changeCity(city)
      this.$router.push('/')
    },
    ...mapMutations(['changeCity'])

  },
  computed: {
    // 将state里面的city映射为currentCity计算属性
    ...mapState({
      currentCity: 'city'
    })
  }
}
</script>
<style lang="stylus" scoped>
@import '../../../assets/styles/var.styl';

.border-topbottom {
  &:before {
    border-color: #ccc;
  }

  &:after {
    border-color: #ccc;
  }
}

.border-bottom {
  &:before {
    border-color: #ccc;
  }
}

.list {
  overflow: hidden;
  position: absolute;
  top: 1.58rem;
  left: 0;
  right: 0;
  bottom: 0;
}

.title {
  line-height: 0.4rem;
  background: #eee;
  padding-left: 0.2rem;
  color: #666;
  font-size: 0.26rem;
}

.button-list {
  padding: 0.1rem 0.6rem 0.1rem 0.1rem;
  overflow: hidden;
}

.button-wrapper {
  float: left;
  width: 33.33%;
}

.button {
  margin: 0.1rem;
  padding: 0.1rem 0;
  text-align: center;
  border: 0.02rem solid #ccc;
  border-radius: 0.06rem;
}

.item-list {
  .item {
    line-height: 0.76rem;
    padding-left: 0.2rem;
  }
}
</style>